cbwjm
Legend
I've thought about going back to 2e rules for raise dead and resurrection and have the caster age several years when casting them. Revivify would be exempt from this rule due to how soon it needs to be used to work. I had thought about using a system shock DC and maybe also lowering the constitution of the raised hero, but I'm not sure I want to be that punishing. The aging thing would be more background than anything as it would explain why people aren't constantly being restored to life. If my players manage to hit 9th level, we'll we don't have a cleric anyway so it still won't really be an issue.
I'm not sure this is as big an issue in 5e as in previous editions. Plenty of people want to play clerics, there are plenty of other classes with access to healing magic, there are plenty of other ways to heal up. This may not actually be the case, but I wouldn't be surprised if the only groups who feel like they need a cleric are players of 3e and earlier, and even 3e didn't rely on having a cleric in the group.
In many groups, playing the cleric is only done reluctantly anyway, by someone who'd prefer to be playing something else but who knows there has to be a cleric for party balance. Piling XP penalties (or whatever) on the reluctant player of a cleric PC for doing the job they feel themselves obliged to do isn't going to make party or group dynamics any better.
I'm not sure this is as big an issue in 5e as in previous editions. Plenty of people want to play clerics, there are plenty of other classes with access to healing magic, there are plenty of other ways to heal up. This may not actually be the case, but I wouldn't be surprised if the only groups who feel like they need a cleric are players of 3e and earlier, and even 3e didn't rely on having a cleric in the group.